c500 y02 lcd display

[Seaeagle166]

Hi new to this so need a bit of help I have a yose power fwd unit 36v 250w with a battery 36v 15.6AHI have a c500 y02 lcd screen all came as part of the kit there is a thumb throttle and when I depress this with the front wheel of the ground I get about 3 to 4 miles per hour is there any way i can increase this there is no setting on the screen for the throttle that I can see any help
Thanks